| 摘要 |
PROBLEM TO BE SOLVED: To provide a lag screw which can be fixed without special expertise in a short time in only one screwing direction and allows stable and easy osteosynthesis and removal permanently without looseness and with a comparatively small force.SOLUTION: A nail and a lag screw are fixed by screwing-in. The lag screw structure provided with a fin whose mechanism slides and expands an engaging part of the lag screw with a synthesized bone by a taper toward the outside of a circumference allows permanent locking without looseness by any free motion of the body of a patient. |
